Kathryn Olson, the civilian director of the Seattle Police Department’s internal-investigations section, announced Tuesday that she plans to step down next year, effectively ending the prospect of bruising confirmation hearings before the City Council to keep her job.

Councilmember Tim Burgess said Tuesday that he met with Olson on Sept. 25 and informed her that her confirmation for reappointment would be “problematic for me” and that he believed she didn’t have the votes to prevail in the nine-member council.

“It unfortunately would signal maintaining the status quo and we have a lot of work to do to rebuild public trust,” Burgess said, referring to the city’s settlement agreement with the Department of Justice in July requiring reforms to curtail excessive force in the Police Department and curb biased policing.

Burgess praised Olson as an “outstanding individual and a true professional,” but said she had been caught in what he called the city’s slowness to adopt substantive police reforms.

Olson, 59, who has headed the Police Department’s Office of Professional Accountability (OPA) since 2007, sent a letter to Mayor Mike McGinn on Tuesday informing him that she planned to depart in the “coming months” and hoped to help implement the reform plan before she leaves.

McGinn nominated Olson to a second term in August, although she had held the job in an acting capacity without required City Council confirmation after her initial three-year term officially expired in May 2010.

McGinn reappointed her to serve until May of next year, when she would have been eligible to seek a third term.

His office attributed the long delay in reappointing Olson to the burden of hiring a new police chief at the outset of his term in January 2010, as well as the Justice Department’s nine-month investigation of the Police Department, which concluded in December, and the subsequent negotiations that led to the settlement.

Olson faced “rigorous” review by the council through the end of the year, including two public hearings and the solicitation of views from community organizations, accountability advocates and the police union about her performance, Bruce Harrell, the chair of the council’s public-safety committee said Tuesday.

“To me, it was not going to be a rubber-stamp process at all,” Harrell said.

In an interview Tuesday night, Olson said she remained willing to undergo the confirmation process but didn’t think it made sense to expend the resources in light of her decision.

Olson, who was first appointed by Mayor Greg Nickels and earned $157,000 last year, said she took issue with Burgess’ assessment of her chances of confirmation based on her own contacts with council members.

She added that her decision to step down had been in the works for some time before her discussion with Burgess.

Harrell said he did not plan to move forward with the hearings and urged McGinn to begin an immediate national search for a new OPA director. He also said Olson should depart “closer to March,” rather than by May as suggested in her letter.

McGinn, in a statement, said, “Kathryn is a dedicated public servant who has worked with great professionalism to guide the Office of Professional Accountability through a time of historic change in our police department. I thank her for her work.”

Olson, in the interview, said she was proud of the work she had done to improve OPA investigations and expressed her gratification that the Justice Department found the overall performance of the office to be sound.

She said she planned to finish some projects and provide advice to the new Community Police Commission to be created as part of the settlement with the Justice Department.

One task of the commission is to evaluate the city’s police-accountability structure, and Olson said her decision to depart gives her the opportunity to speak with “no skin in the game.”

In her letter to McGinn, she wrote, “My experience as President of the National Association for Civilian Oversight of Law Enforcement (NACOLE) and in speaking around the country about the strengths and weaknesses of alternative oversight models will be useful in working with the Commission.”